How long does it take for HRT to start working?

You've started HRT. It's been ten days. You still can't sleep, you're still throwing the duvet off at 3am, and you're beginning to wonder whether it's doing anything at all.

The short answer: a few weeks before you feel any benefit, and up to three months for the full effect. Ten days is too early to judge.

The timeline, from the NHS

Guy's and St Thomas' NHS Foundation Trust puts it plainly: it usually takes a few weeks before you feel the benefits of HRT, and it can take up to three months to feel the full effects. If you haven't felt the benefit after four to six months, it may help to try a different type.

NHS inform frames it the same way: once you've started, it's best to take it for a few months to see whether it works for you. If it doesn't, you can try a different type or increase the dose.

So there are two numbers worth holding onto:

• Three months — how long to give it before deciding whether it's working
• Four to six months — the point at which the NHS suggests a different type may be worth trying

Those are further apart than most people expect, and further apart than the internet usually suggests.

What we're not going to tell you

You'll find week-by-week timelines all over the internet. Week one: better sleep. Week three: fewer hot flushes. Month two: clearer thinking. They're oddly specific and they're almost all published by clinics selling HRT.

We couldn't source that level of detail to UK guidance, so we're not going to repeat it. What the NHS says is "a few weeks" and "up to three months", and that's what we can stand behind.

The honest position is that it varies — by the type of HRT, the dose, the route, the symptom and the person. A precise-sounding timeline gives false comfort, and then makes you feel like something's wrong with you when your week four doesn't match the chart.

Four reasons it might seem not to be working

This is the part worth knowing, because "it isn't working" and "it isn't working yet" look identical from the inside.

1. You might be on the wrong type for that symptom.

This one catches people out. Local vaginal HRT — creams, pessaries, rings, vaginal tablets — contains a small amount of oestrogen and works only in the area where you put it. Guy's and St Thomas' are explicit: local HRT does not help other symptoms such as hot flushes, and it doesn't protect against longer-term effects like osteoporosis.

So if you were prescribed a vaginal preparation and you're waiting for your hot flushes to stop, they won't. That's not a failure of the treatment. It's the wrong tool for that particular job, and it's a conversation with your GP rather than a waiting game.

2. The dose may need adjusting.

NHS guidance on starting HRT notes you'll usually begin on a low dose, which may be increased later depending on how well it works and whether you get side effects. Starting low is deliberate. It also means the first dose you're given isn't necessarily the one you'll settle on.

3. Something else may be clearing it faster than it should.

St John's wort speeds up the liver enzymes that break down hormones, which can quietly make HRT less effective while you assume the dose is wrong. If you're taking anything from the supplement aisle, it belongs on the list you give your GP — we've written about which supplements matter with HRT separately.

4. You may have been given a different brand.

NHS inform notes there are ongoing supply problems with some HRT products, and that if your pharmacy can't supply the specific product you were prescribed, they may supply an alternative — usually the same ingredient, made by a different manufacturer. Worth knowing if what came out of the bag didn't look like what you expected.

What to do while you wait

Write it down. Not because tracking is virtuous, but because improvement is often gradual enough that you don't notice it happening. Score your sleep, your flushes and your mood out of five each day, and in six weeks you'll have something more reliable than memory to take to your GP. Our free printable planner has a log built into it.

Don't stop early because nothing's happened in a fortnight. The NHS number is three months. Two weeks tells you very little.

Do speak to your GP if something's actively wrong. Side effects can arrive before the benefits do. That's a reason to talk to someone, not a reason to quietly give up.

The summary

A few weeks for the first change. Up to three months for the full effect. Four to six months before the NHS suggests trying a different type.

If you're four weeks in and impatient, that's completely reasonable and also completely normal. If you're four months in and nothing has shifted at all, that's worth an appointment rather than more patience.